NIIKA differential rings (friction rings), also known as slip rings, are critical components for industrial web handling machines (such as slitting, rewinding, coating, laminating machines and other take-up shafts). They are specifically designed to address issues like wrinkles, breaks, or deviations caused by uneven material tension and linear speed differences during the winding process. As a key part of the differential shaft, their core function lies in a self-regulating differential compensation mechanism through friction. This dynamically adjusts the speed difference of each roll in response to variations in material thickness, tension requirements, or rotational speed, achieving consistent linear speed and constant, controllable tension. They are widely used in precision slitting and winding operations for plastic films, printing, packaging, textiles, and other materials.